Valve silencer



Feb; 25, 1930. F. M. KxNcAlD 1,748,718

i VALVE SILENCER Filed April 23, 1928 2 Sheets-Sheet 1 @mmf @rank WZ. fwazld. l

F. M. KINCAID Feb. 25, 1930.

VALVE SILENCER 2 Sheets-Sheet 2 Filed April 23, 1928 Patented Feb. l

' UNITED )STATES[PATENT"QFFICE, i FRANK MfKINcArDQ or tinta, cino,l assienonor rnnnn-roniarns'ro WKILLIKAivI n. BAssicK, orrisiainenronr, connncricur VALVE.V SILENCEB l Application mea April 2s, 1928. serialy No. 272,054..

` This invention relates tol improvements in On the drawings: l j

the poppet valve operating mechanisms f inf ternal combustion engines, 4*and has special reference to silencing and reducing the impact between the `valve stem and `its operating mechanism. f

It is well-known that in a poppet valve type engine a clearance between 'the valve stem f io and .tappet' is necessary when the valve is `closed,-ifor the reasonthat heating and eX-y pansion of thevalve'stem' and engine cylinder 1 occur` aty different rates when in operation, so Athatwith an unduly small initial clearancethe valve may actually be held off its seat when it should-be closed. `LThe necessary clearance'results inan impact or blow each time the valve is opened, and alsoiwhen the valvereturns to kits seat because'they closingvelocity of the valve cannot be stopped completely dueto the necessity ofsuch a clearance.

It is therefore-an obfect of thisinvention toV provi-de an -improveddevice `for, `silencing vor reducing the impact dueto this clearance. Y

chamber 12 indicated` abovev the cylinder I norder to accomplish this 'resultl I have provided an improved Yoperating j mechanism adapted to provide apositiveand timed open-` ring` andclosing ofthe jvalve' that is substanto insure initial and renewed proper timing .I classdescrib'ed which canbe .manufactured at j ytially noiseless inoperatio'nyand that provides y a compensating feature automatically providingfor normal wear and=manually adjustable It is also an objectief thi-s'inv-entionto re-V lieve the valve stem proper of the direct load or pressure of the valve spring and to transfer guide. y Y It is another object of this inventionto-provide an improved and simpli-ie'd'deviceof the l a reasonable cost and will bereliable i'n use.

y drawings, Y f

l Y This invention (in a preferred form) is-iL Other and further important objects of this invention will be apparent from the disclosures in the specification and the accompanying lustrated in the drawings andhereinafter morefully des cribfed.` V

lshown on thedrawings Figure 1-is a fragmental vertical section through the cylinder of an engine showing g one form of the ,valve operating mechanism of this invention 'partly in elevation.

Figure 2 is'a section on theline II-'II of Figurel. f 7

Figure 3 is a section,.partly in elevation, of another embodiment of theinvention. f

Figure 1' is af. section, partly in elevation, of a third embodiment of the invention.

Figure 5is a section, partly in elevation, y

tion comprise the cylinder block-including thewallyl'Oand piston llfwith a combustion block, together with a valve seat 13 and intake or exhaust gas passagel formed in the cylinder block. The usual cam shaft 15 is shown with cams thereon which act againstthe' bot'- tom of a mushroom' type ofcamfollower or tappet-l sliding in a tappet guide bushing 17 .f Theupperlend of the tappet carries an adjustable set' screw y18 with .a'loclr nut 19 for .adjusting the valve Vstem clearance.

' A poppetvalve ofthe usual form comprises a headjportion 2O and-a stem21 sliding in a valve'stem guide 22 inserted in-a boss `23 7; is a section, partly in elevation, of

formed. intliecylinder block in alignmentl vwith thetap-pet and valve seat. The valve head is held against its seat byV a valve spring e 24, one end offwhichbears against the underside of the cylinder block around the boss 23,'

the other end'of the springresting in a spring retainer 25which1` is heldv in positionfon a 1 lower valve stem 26 by means of `a locky 27. In an ordinary valve the lower stem 26 forms -a' continuation ofthe stem'21, lwhereas in the various embodiment-s {of this invention a 'separate-.part 1; n

Inltheembodimentof `this lnvention, Shown the lower stem 2G is i in Figure 1 the valve stem 21 and the lower stem 26 are looth reduced in diameter for a short distance back from their adjacent ends to form pilots 28 and 29, which are continued tor an equal distance as a shallow semi-circular section.toengagetwoor three oithe end coils ota closely Wound spring 30, whic'liacts to pull the upper valve stem downwardly thus seating vthe valve. The.extremeendsl of the spring 30 are formadas inturnedpins engaging in radial holes drilled into the valve stems.

In the operation of this form of valve structure it will loe evident that the main Valve spring 24 acts directly against the lower vaive stem, which in turn presses=on the tappet to causewitfat-:all times to `follow theicam. The

inner spring 180 facts lin :tension Eto pull fthe vvalve stem 21. downwardly andis'madeilighter than the main valve spring,fso that awhen the .valve headseats the lowerstem follows the cam and establishes the proper clearance Ybetween theitwo pilots @Sand-29, as indicated plete=valveiinthe cylinder block.

In Figure 4 no lpilots are formedon the valvestems, a `spring `loeingfslipp'ed over the adjacent ends which .are separated Vloy slightlyyielding ibcr-washers 6,the spring `ends being .welded Ito :their :respective :stem iportions,ras indicated by the .numeral B7.

The modification of Figure l5 4utilizes a stirrup or strap 38 enveloping-collars189 Iinsorted in f grooves -in ithe upper andlower stems, respectively. A spring 40 is Vinserted hetweenfthe lower end of1 the fstirrup and the collar 139 .-on the lower xstem 26, .and fa pilot .1441 .is iormed Aon the upper lendroit :the lowerstenrtoreceive a-seeond spring 42. The

second s pringis lintended tol assistthev maintenanceoftia clearancei'hetweenthe adjacent ends of the-pilot 41 and ythe upper Ystem 21,

-whil'efthe lspring 40 .transmits the pressure of'f Vthe mainl s pring thro ugh. thestirrup' to fthe up per :valve stem and. head, *this spring thus 'holding the'valvelhead-to its seat.

Theanodification of Figures 7 and 8 em- -hodies fa lost Imotion fconnec-tion -loetween 1the two `vvalve" stems, this connection comprising Ei'nterenga'g'ing oppositely offset flugs 43 formed onJ the adj aeentends of :the stems ,fthe

in Figure 7 the clearance has been taken uphy fanupward-movementofthe lowerstem .pre-

paratory to opening the valve. Normally the relatively heavy outer main 'spring would cause the clearance to be taken on the other sides of the lugs during the closed period of the valve.

llt-will thushe seen that l have-provided an improved and simplified valve silencing device that materially reduces shock and wear lin the valve mechanism 'l am aware that many changes may he made and numerous details of construction maybe-varied thro-ugh a wide range without departing from the principles. of this insvention,-,andflztherefore do not purpose limiting the patent granted hereon, otherwise th an necessitated fhyithe prior art.

Y PI-claim as imygnvention 1. valve :mechanism Vof =the class (delscribed comprising spaced upper and lower :valve stems, La ispring connecting: Said stems, said spring being initially tensionedpand a main aval/ve :spring engagingth-e lower zvalve stem adapted Ito cause thenlatter to closely ifollow fthe @valve operating mechanism.

2. poppet'valve structure comprising a vtwo-piece fstem, a valve-spring adapted to lforce the :lower stem Vsection downwardly, and a lighter spring ljoining the two stem sections and .adapted i to pull the upper y stem section-downwardly. to cause seating of said a valve 3; Aavalve kmechanism 'ofthe class described comprising an operating mechanism embodying a ftwo-piece rod, ione rpiece of which is adjacentlthepvalve proper andthe 4other tmovahle'relative thereto :and follows fthe; operating mechanism,v a ftensioned .spring ,connectingithe ztwo lpieces, and a Amainvalve springvrhaving -its 'movable end engaged with @the second rod piece.

A ivalve operating stem comprising spaced yupper .and llower segments, vmeans yieldingly connecting 4said segments, and a valve spring` operatively :engagingthe slower segmentof said stern.

"5. AA :valve y:actuating =stem,r-a lseparate spaced extension thereof, means yieldingly -urging said stem and vextension together, and `means :acting on said' extension adapted to :seatsaid valve. i

f6. A val-ve operating Ast-em comprising spaced upper-'and lower segments, a spring :yieldingly connecting :said segments, and a valve spring operatively engaging thelower -segmentfotsaid stem.

17.11 valve nactuating stem, ya :separate spaced extensionthereof, av spring yieldingly urging lsai'drstem and extension together, and 'means acting on said i extension adapted nto seat sai'd valve.

f8. A fvalve mechanism of 'the class described comprising an operating mechanism embodying a-two-piece rod, Ione piece of Iwhich Ii's adjacent gthe waive proper and -lthe other movable relative `thereto and :follows LIS() the operating mechanism, meansl yieldingly y connecting the two pieces and a main valve spring having its movable end engaged with thevsecond rod piece. s

9. A valve operating mechanism comprising a two-piece valve stem, a tappet engaged by the lower piece ofthe valve stem, a spring connecting the lower piece to the upper .piece of the stem, vand a valve spring engaging the lower piece of the stem and adaptedpto 1 cause it to'ollow said tappet.

lO. Atwo-piece valve stem, a spring con-` necting the two pieces of the stem, anda stronger valve spring engaging that portion of the stem not associated with the valve whereby the latter portion is adapted to in# dependently follow p the valve operating mechanism.

` 11. A valveoperating train comprising a valve and a camshaft, a cam follower, means adapted to maintain said followervin contact with its cam on said cam shaft and yield- A:as

ing means kconnecting -said last mentione means to the valve. Y

n 12. A valve operating'train comprising a i valve and a camshaft, a cam follower, .a spring adaptedto maintain said followerk in contactrwith its cam on the camshaft and a lighter spring opposed to said rst menl tioned spring and adapted to urge said valve towards said cam follower.

In'testimony whereof I have hereunto subscribed my name at Chicago,` Cook County,

Illinois.

" FRANK M.; KINCAID. Y

-eoy 

